This disclosure relates to a system and method for monitoring a power line.
In earlier times the measurement of low level currents on ground conductors, signal cables, and other physical structures has been used as diagnostic tools for power quality analysis. Ground currents are measured in order to detect an unwanted connection between system conductors or with ground. Ground currents can be evidence of a damaged power system, such as when a tree falls on a power line. Undetected ground faults can cause problems with different production and/or industrial processes. Thus, unnoticed ground faults can damage or even shutdown equipment, affecting productivity. Additionally, ground faults can result in dangerous voltage that poses potential health and safety risks such as fire or electric shock.
Over time, monitoring systems for ground and phase currents have evolved. The most basic is a system directly connected to a power line by a cable wire. The cable wire attaches the power line to a monitoring system, which performs calculations regarding voltage, ground and phase currents. However, the problem with a directly wired system is the danger of damaging the monitoring equipment if the power lines short circuit or are ever struck by lightning. More recently, a wireless system has developed in which the monitoring system wirelessly measures phase shifts between voltage and current, for each line. However, the problem with present power line monitoring systems is that although they can currently calculate voltage and phase currents on each individual power line, they are unable to do any calculations that look at all the lines together, such as calculating ground current.
As such it would be useful to have an improved system and method for measuring phase and ground currents on a power line.